Prepare the tuna: Cut the tuna into 1-inch cubes using a sharp knife for clean cuts.
- Make the marinade: In a bowl, whisk together soy sauce, sesame oil, rice vinegar, honey, grated ginger, garlic powder, and chili flakes (if using).
- Marinate the tuna: Place tuna in a shallow dish, pour the marinade over it, toss gently, and refrigerate for 15-20 minutes.
- Prepare the rice and toppings: Cook rice as per package instructions. Slice the cucumber, avocado, radishes, and chop the scallions.
- Assemble the poke bowls: Place a scoop of rice in each bowl, top with marinated tuna, cucumber, avocado, radishes, and any other toppings.
- Garnish: Sprinkle sesame seeds and drizzle extra sesame oil or soy sauce. Add edamame, seaweed salad, and pickled ginger on the side.
- Serve and enjoy: Serve immediately while fresh or refrigerate components separately for later assembly.